Furnace roll assembly

ABSTRACT

A roller assembly for moving a billet in a furnace comprising a rotatable shaft, a roller and at least one support member. The roller has an outer rolling surface for accepting the billet thereon. The roller further includes an inner surface. The at least one support member is located between the rotatable shaft and the roller. The at least one support member includes a support surface engaging the inner surface of the roller, whereby the support surface provides support for the rolling surface of the roller, thereby preventing cracking or indenting of the rolling surface as the billet strikes the rolling surface.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present invention claims priority to Provisional PatentApplication No. 60/301,208, filed on Jun. 27, 2001 entitled FURNACE ROLLASSEMBLY.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a roller assembly, and inparticular to a roller assembly for use in a high temperature furnace.

[0003] Furnaces are used to heat objects to an elevated temperature.Furnaces are also used to heat treat objects placed therein to lengthenthe life of the object or to provide the object with a particulardesired characteristic that can be developed through heat treatment.Furnaces are further used to heat objects so the objects becomemalleable such that the objects can easily be formed into a certainshape or cut.

[0004] Heretofore, furnaces have had inlets and outlets whereby a objectcan be placed into the inlet, heated in the furnace and removed from theoutlet. Sometimes, the inlet can also work as the outlet. When theobject placed into the furnace is a cylindrical billet, furnaces haveincluded a plurality of rollers extending across the furnace thatsupport the billet and move the billet from the inlet to the outlet ofthe furnace. The rollers typically have a cylindrical surface with atrough thereon for maintaining the billet in the trough of the roller.One problem experienced in the prior art is that when the furnacereaches temperatures of approximately 2200-2400° F., the leading edge ofthe billet can begin to sag downward under the force of gravity becauseof the malleability of the billet due to the extreme heat. When theleading edge of the billet sags, the circumferential surface of thebillet directly adjacent the leading edge of the billet will not moveonto the cylindrical surface of the next roller in the line between theinlet and the outlet as the billet engages the next roller. Instead, theleading edge of the billet can strike the cylindrical surface. At suchextreme temperatures, the cumulative force of many billets striking theroller can cause the roller to deform and sometimes crack. Typically,the roller had to be replaced about every month or every two months.Replacing rollers usually cost large amounts of money because a rollerused in a furnace reaching temperatures of approximately 2200-2400° F.is expensive to manufacture. Furthermore, as the roller is beingreplaced, the furnace can not be used. Therefore, the manufacturer usingthe furnace will lose money for the time that the furnace cannot be usedto produce forged objects, as well as the time necessary for the furnaceto cool prior to repairs and the time necessary to reheat the furnaceafter such repairs. Accordingly, a practical, economical roller that canbe easily manufactured and that has a long operating life is desired.

SUMMARY OF THE INVENTION

[0005] The aforementioned drawbacks of the prior art have been elegantlyresolved through the present invention, which provides a roller assemblyfor moving a billet in a furnace comprising a rotatable shaft, a rollerand at least one support member. The roller has an outer rolling surfacefor accepting the billet thereon. The roller further includes an innersurface. The at least one support member is located between therotatable shaft and the roller. The at least one support member includesa support surface engaging the inner surface of the roller, whereby thesupport surface provides support for the rolling surface of the roller,thereby preventing cracking or indenting of the rolling surface as thebillet strikes the rolling surface.

[0006] Another aspect of the present invention is to provide a furnacehaving a furnace housing and a plurality of roller assemblies. Thefurnace housing has an inlet and an outlet. The furnace housing isconfigured to accept a billet through the inlet and to eject the billetthrough the outlet, where the billet has a direction of travel throughthe furnace housing. The plurality of roller assemblies are locatedwithin the furnace housing. Each roller assembly comprises a rotatableshaft, a roller and at least one support member. The roller has an outerrolling surface for accepting the billet thereon and an inner surface.The at least one support member is located between the rotatable shaftand the roller. The at least one support member includes a supportsurface engaging the inner surface of the roller, whereby the supportsurface provides support for the rolling surface of the roller, therebypreventing cracking or indenting of the rolling surface as the billetstrikes the rolling surface.

[0007] The principal objects of the present invention include providinga furnace roll assembly having a long operating life. The furnace rollassembly is efficient in use, economical to manufacture, capable of along operable life, and particularly adapted for the proposed use.

[0008] Other objects, advantages and features of the invention willbecome apparent upon consideration of the following detaileddescription, when taken in conjunction with the accompanying drawings.The above brief description sets forth rather broadly the more importantfeatures of the present disclosure so that the detailed description thatfollows may be better understood, and so that the present contributionsto the art may be better appreciated. There are, of course, additionalfeatures of the disclosure that will be described hereinafter which willform the subject matter of the claims appended hereto.

[0009] In this respect, before explaining the preferred embodiment ofthe disclosure in detail, it is to be understood that the disclosure isnot limited in its application to the details of the construction andthe arrangements set forth in the following description or illustratedin the drawings. The furnace roll assembly of the present disclosure iscapable of other embodiments and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein are for description and not limitation.Where specific dimensional and material specifications have beenincluded or omitted from the specification or the claims, or both, it isto be understood that the same are not to be incorporated into theappended claims.

[0010] As such, those skilled in the art will appreciate that theconception, upon which this disclosure is based, may readily be used asa basis for designing other structures, methods, and systems forcarrying out the several purposes of the present invention. It isimportant, therefore, that the claims are regarded as including suchequivalent constructions as far as they do not depart from the spiritand scope of the present invention.

[0011] Further, the purpose of the Abstract is to enable the U.S. Patentand Trademark Office and the public generally, and especially thescientists, engineers and practitioners in the art who are not familiarwith the patent or legal terms of phraseology, to learn quickly from acursory inspection the nature and essence of the technical disclosure ofthe application. Accordingly, the Abstract is intended to define neitherthe invention nor the application, which is only measured by the claims,nor is it intended to be limiting as to the scope of the invention inany way.

[0012] These and other objects, along with the various features andstructures that characterize the invention, are pointed out withparticularity in the claims annexed to and forming a part of thisdisclosure. For a better understanding of the furnace roll assembly ofthe present disclosure, its advantages and the specific objects attainedby its uses, reference should be had to the accompanying drawings anddescriptive matter in which there are illustrated and described thepreferred embodiments of the invention.

[0013] While embodiments of the furnace roller assembly are hereinillustrated and described, it is to be appreciated that various changes,rearrangements and modifications may be made therein, without departingfrom the scope of the invention as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a top schematic view of a furnace of the presentinvention.

[0015]FIG. 2 is a front view of a furnace roller assembly having across-section view of a locking collar and a roller of the presentinvention.

[0016]FIG. 3 is a side view of the furnace roller assembly of thepresent invention taken from the right side of the furnace roller asseen in FIG. 2.

[0017]FIG. 4 is a front view of a trunnion cast of the presentinvention.

[0018]FIG. 5 is a side view of the trunnion cast of the presentinvention taken from the right side of the trunnion cast as seen in FIG.4.

[0019]FIG. 6 is a cross-sectional view of a drive trunnion of thepresent invention taken along the line VI-VI of FIG. 2.

[0020]FIG. 7 is a side view of a locking collar of the presentinvention.

[0021]FIG. 8 is a cross-sectional view of the locking collar of thepresent invention taken along the line VIII-VIII of FIG. 7.

[0022]FIG. 9 is a partial top view of the locking collar showing afinger of the present invention.

[0023]FIG. 10 is a side view of a furnace roller of the presentinvention.

[0024]FIG. 11 is a cross-sectional view of the roller of the presentinvention taken along the line XI-XI of FIG. 10.

[0025]FIG. 12 is a cross-sectional view of the roller of the presentinvention taken along the line XII-XII of FIG. 11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] For purposes of description herein, the terms “upper,” “lower,”“right,” “left,” “rear,” “front,” “vertical,” “horizontal,” andderivatives thereof shall relate to the invention as orientated inFIG. 1. However, it is to be understood that the invention may assumevarious alternative orientations, except where expressly specified tothe contrary. It is also to be understood that the specific devices andprocesses illustrated in the attached drawings, and described in thefollowing specification are simply exemplary embodiments of theinventive concepts defined in the appended claims. Hence, specificdimensions and other physical characteristics relating to theembodiments disclosed herein are not to be considered as limiting,unless the claims expressly state otherwise.

[0027] The reference number 10 (FIG. 1) generally designates a furnaceof the present invention. The furnace 10 includes a plurality of rollerassemblies 12 obliquely extending across the furnace 10. Each rollerassembly 12 includes a roller 14 in the middle section of the rollerassembly 12. The rollers 14 of the roller assemblies 12 are aligned in arow. The rollers 14 are configured to accept a cylindrical object 16,such as a billet, on a roller surface 18 of the rollers 14 as thecylindrical object 16 is forced into the furnace 10. Preferably, thecylindrical object 16 is a steel billet used to make bearing components,although it is contemplated that other cylindrical materials used forother purposes can be forced into the furnace 10. Accordingly, in thepreferred embodiment, the furnace 10 can reach temperatures ofapproximately 2200-2400° F. The cylindrical object 16 is forced into thefurnace 10 by a conveyor 20 at one end of the furnace 10 at the inletthereof and forced onto consecutive rollers 14 of the roller assemblies12 and passed through to an outlet thereof. Preferably, the furnace 10includes thirty roller assemblies 12. Additionally, the rollers 14 ofthe roller assemblies 12 are preferably positioned at approximately a 7°angle relative to a line perpendicular to the cylindrical object 16 inorder to rotate the cylindrical object 16 to obtain even heating of theobject 16. Each roller assembly 12 includes a driven end 22 connected toa motor 24 for rotating the roller assembly 12 and an idler end 26connected to an idler housing 28 for allowing the roller assembly 12 torotate. Preferably, the roller assemblies 12 are rotated in a clockwisedirection relative to the direction of travel of the cylindrical object16 with the rollers 14 offset 7° downstream of motor 24.

[0028] The illustrated roller assembly (FIGS. 2 and 3) includes a hollowcylinder 30, the roller 14, a locking collar 32 locking the roller 14 tothe cylinder 30, a driven trunnion 34 on a first end of the cylinder 30and an idling trunnion 36 on a second end of the cylinder 30. The hollowcylinder 30 is preferably a centrifugally cast tube. The driven trunnion34 is activated by the motor 24 to rotate the cylinder 30, the lockingcollar 32 and the roller 14. Likewise, the idling trunnion 26 is placedinto the idler housing 28 to support the second end of the cylinder 30and to allow the cylinder 30, locking collar 32 and the roller 14 torotate. Although the cylinder 30 is shown as being annular, it iscontemplated that the cylinder could have other cross-sectionalconfigurations, including triangular, square and hexagonal.

[0029] In the illustrated example, the driven trunnion 34 and the idlertrunnion 36 are made by first forming a trunnion cast 38 (FIGS. 4 and 5)and then milling, machining or otherwise removing portions of thetrunnion cast 38 to form the driven trunnion 34 and the idler trunnion36. The trunnion cast 38 includes an annular connecting portion 40, anannular enlarged ring portion 42 and an annular finger portion 44. Thetrunnion cast 38 also includes a bore 46 having a first portion 48within the connection portion 40, a second larger portion 50 within theenlarged ring portion 42 and a third portion 52 partially through thefinger portion 44. The annular finger portion 44 of the trunnion cast 38is worked to form the driven trunnion 34 and the idler trunnion 36.

[0030] The illustrated driven trunnion 34 (FIGS. 2 and 6) is connectedto the cylinder 30 of the driven end 22 of the roller assembly 12. Asbest seen in FIGS. 2 and 6, the finger portion 44 of the trunnion cast38 is formed into an annular portion 54 adjacent the ring portion 42, ahexagonal portion 56 adjacent the annular portion 54, a first discportion 58 adjacent the hexagonal portion 56, a second larger discportion 60 adjacent the first disc portion 58 and an end key portion 62at the end of the finger portion 44. The key portion 62 includes akeyway 64 transversely through the end of the key portion 62. The keyway64 is engaged with a key (not shown) in the motor 24 to rotate theroller assembly 12. The driven trunnion 34 is connected to the cylinder30 by inserting the connection portion 40 into an opening at the firstend of the cylinder 30. The connection portion 40 is inserted into thecylinder 30 until the enlarged ring portion 42 abuts against thecylinder 30. The enlarged ring portion 42 and the cylinder 30 are thenwelded together at a weld ring 65.

[0031] In the illustrated example, the idler trunnion 36 (FIGS. 2 and 3)is connected to the cylinder 30 at the idler end 26 of the rollerassembly 12. As best seen in FIG. 2, the finger portion 44 of thetrunnion cast 38 is formed into a hexagonal portion 66. The hexagonalportion 66 is engaged with a mating idler (not shown) in the idlerhousing 28 to allow the roller assembly 12 to rotate. The idler trunnion36 is connected to the cylinder 30 by inserting the connection portion40 into an opening at the second end of the cylinder 30. The connectionportion 40 is inserted into the cylinder 30 until the enlarged ringportion 42 abuts against the cylinder 30. The enlarged ring portion 42and the cylinder 30 are then welded together at a weld ring 68.

[0032] The illustrated locking collar 32 (FIGS. 7-9) is placed in themiddle of the cylinder 30 and locks the roller 14 to the cylinder 30 andprovides support for the roller surface 18 of the roller 14. The lockingcollar 32 includes a cylindrical skirt portion 70, an open disc-shapedportion 72 at one end of the skirt portion 70 and a plurality of fingerportions 74 extending from a periphery of the disc shaped portion 72.Each of the finger portions 74 includes a tapering portion 76 extendingtowards the axis of the locking collar 32 and away from the periphery ofthe disc shaped portion 72. The tapering portion 76 includes a pair ofside edges 80 converging towards each other at a first end 82 connectedto the disc shaped portion 72 and a second end 84. Each finger portion74 also has a flange portion 78 extending from the second end 84 of thetapering portion 76 towards the axis of the locking collar 32. Theflange portion 78 of the finger 74 is parallel to the disc shapedportion 72. Preferably, the locking collar 32 includes eight fingers 74.The fingers 74 assist in connecting the roller 14 to the locking collar32. The locking collar 32 is preferably formed of SL96D alloy, an alloysold by Steeltech Ltd. of Grand Rapids, Mich.

[0033] In the illustrated example, the roller 14 (FIGS. 10-12) ispositioned in the middle of the cylinder 30 and provides a support forthe cylindrical object 16 in the furnace 10. The roller 14 includes ashell 86, preferably having an hourglass, or V, shaped outer surfacedefining the roller surface 18. Of course, arcuate outer surfaces may beused to define the roller surface 18. The shell 86 has a hollow interior88. The interior 88 of the shell 86 includes a plurality of slots 90conforming to the outside shape of the fingers 74 of the locking collars32. The roller 14 preferably includes a number of slots 90 equal to thenumber of fingers 74 on the locking collars 32. Therefore, in theillustrated example, the roller 14 includes eight slots 90.Consequently, each side of the shell 86 has a funnel shaped opening 92which includes a plurality of radially extending tabs 94 defining theslots 90. The shell 86 also includes a center inner hub 96. The roller14 is also preferably formed of SL96D alloy as sold by Steeltech Ltd. ofGrand Rapids, Mich.

[0034] The illustrated roller 14 and locking collars 32 are connected tothe cylinder 30 by first inserting the cylinder 30 into the hollowinterior 88 of the shell 86 of the roller 14. Consequently, the innerhub 96 of the shell 86 has an inner diameter slightly larger than theouter diameter of the cylinder 30 such that the roller 14 will fit ontothe cylinder 30. One locking collar 32 is then slid towards the centerof the cylinder 30 from each end of the cylinder 30, with the fingers 74of the locking collar 32 facing the center of the cylinder 30. Thelocking collars 32 are then slid into the roller 14 by inserting thefingers 74 on the locking collar 32 into the slots 90 of the roller 14until the tapering portion 76 of the fingers 74 abut the inner hub 96 ofthe roller 14. The locking collars 32 are then held in position in themiddle of the cylinder 30 by drilling a hole 98 through the cylindricalskirt portion 70 of the locking collar 32 and the cylinder 30. A pin 100is then inserted into the hole 98 and welded to the locking collar 32 tomaintain the locking collar 32 from torsional and transverse motions,and therefore the roller 14, in position (see FIG. 2). The lockingcollar 32 is also welded to the cylinder 30 to maintain the operationalintegrity of the roller 14 and the locking collar 32. The roller 14 andthe locking collar 32 solves any cracking or indentation of the rollsurface 18 of the roller 14 and locks the roller 14 against linear andtorsional motions caused by the force of the cylindrical object 16against the roll surface 18 when the cylindrical object 16 is forcedinto the furnace 10 and onto the rollers 14.

[0035] In the illustrated example, the fingers 74 of the locking collar32 are positioned against the inside surface of the funnel shapedopening 92 of the roller 14. Consequently, the fingers 74 providesupport for the underside of the roller surface 18 of the roller 14.Therefore, when cold cylindrical objects 16 are forced into the furnace10 and onto the roller surfaces 18 of the rollers 14, the roller surface18 will not deform if the cylindrical objects 16 are forced into,instead of on, the roller surfaces 18. With the support formed by thefingers 74, the roller surfaces 18 will be able to withstand the impactof the cylindrical objects 16 to force the cylindrical objects intoproper position on the rollers 14. Moreover, the clockwise rotation ofthe rollers 14, coupled with the 7° offset, tends to lift the leadingedge of the cylindrical object 16 as if the cylindrical object 16 isitself rotated in a counter-clockwise direction relative its directionof travel, further minimizing impacts and damage.

[0036] In the forgoing description, it will be readily appreciated bythose skilled in the art that modifications may be made to the inventionwithout departing from the concepts disclosed herein. Such modificationsare to be considered as included in the following claims, unless theseclaims by their language expressly state otherwise.

We claim:
 1. A roller assembly for moving a billet in a furnacecomprising: a rotatable shaft; a roller having an outer rolling surfacefor accepting the billet thereon, the roller further including an innersurface; and at least one support member located between the rotatableshaft and the roller, the at least one support member including asupport surface engaging the inner surface of the roller, whereby thesupport surface provides support for the rolling surface of the roller,thereby preventing cracking or indenting of the rolling surface as thebillet strikes the rolling surface.
 2. The roller assembly of claim 1,wherein: the at least one support member comprises a pair of lockingcollars locking the roller to the rotatable shaft.
 3. The rollerassembly of claim 2, wherein: the locking collars include a plurality offingers defining the support surface; the roller includes a plurality ofslots conforming to the shape of the fingers and defining the innersurface; and the fingers engage the slots to lock the roller onto therotating shaft and to rotate the roller with the rotating shaft.
 4. Theroller assembly of claim 3, wherein: the rolling surface of the rolleris non-linear and is thereby adapted to force the billet thereon into acenter area of the rolling surface.
 5. The roller assembly of claim 3,wherein: the inner surface of the roller is generally parallel toadjacent portions of the rolling surface of the roller.
 6. The rollerassembly of claim 5, wherein: the support surface of the locking collaris generally parallel to the inner surface of the roller.
 7. The rollerassembly of claim 3, wherein: the roller includes a central inner hubcontacting the rotatable shaft, the central inner hub dividing the innersurface of the roller into a first inner surface and a second innersurface.
 8. The roller assembly of claim 7, wherein: ends of the fingersof the locking collars abut a side of the central inner hub of theroller.
 9. The roller assembly of claim 7, wherein: the first innersurface includes a plurality of first depending tabs dependingtherefrom, the first depending tabs defining a first set of the slots;and the second inner surface includes a plurality of second dependingtabs depending therefrom, the second depending tabs defining a secondset of the slots.
 10. The roller assembly of claim 9, wherein: the firstand second depending tabs are integral with the central inner hub; andthe first and second depending tabs are tapered in a direction movingaway from the central inner hub.
 11. The roller assembly of claim 10,wherein: each locking collar includes a skirt surrounding the rotatableshaft, a flange extending away from the skirt, and the fingers; and thefingers extend away from the flange in a direction opposite to the hub.12. The roller assembly of claim 11, wherein: the fingers taper in adirection moving away from the flange.
 13. The roller assembly of claim12, wherein: each of the fingers include a tab extending therefrom, andeach of the tabs abuts a side of the central inner hub of the roller.14. The roller assembly of claim 13, wherein: the tab extends in adirection parallel to the direction of the flange.
 15. The rollerassembly of claim 1, wherein: the rotatable shaft is hollow.
 16. Afurnace comprising: a furnace housing having an inlet and an outlet, thefurnace housing configured to accept a billet through the inlet, thefurnace housing further configured to eject the billet through theoutlet, the billet having a direction of travel through the furnacehousing; and a plurality of roller assemblies located within the furnacehousing, each roller assembly comprising a rotatable shaft, a roller andat least one support member; wherein the roller has an outer rollingsurface for accepting the billet thereon, the roller further includingan inner surface; and wherein the at least one support member is locatedbetween the rotatable shaft and the roller, the at least one supportmember including a support surface engaging the inner surface of theroller, whereby the support surface provides support for the rollingsurface of the roller, thereby preventing cracking or indenting of therolling surface as the billet strikes the rolling surface.
 17. Thefurnace of claim 16, wherein: the at least one support member comprisesa pair of locking collars locking the roller to the rotatable shaft. 18.The furnace of claim 17, wherein: the locking collars include aplurality of fingers defining the support surface; the roller includes aplurality of slots conforming to the shape of the fingers and definingthe inner surface; and the fingers engage the slots to lock the rolleronto the rotating shaft and to rotate the roller with the rotatingshaft.
 19. The furnace of claim 18, wherein: the rolling surface of theroller is non-linear and is thereby adapted to force the billet thereoninto a center area of the rolling surface.
 20. The furnace of claim 18,wherein: the inner surface of the roller is generally parallel toadjacent portions of the rolling surface of the roller.
 21. The furnaceof claim 20, wherein: the support surface of the locking collar isgenerally parallel to the inner surface of the roller.
 22. The furnaceof claim 18, wherein: the roller includes a central inner hub contactingthe rotatable shaft, the central inner hub dividing the inner surface ofthe roller into a first inner surface and a second inner surface. 23.The furnace of claim 22, wherein: ends of the fingers of the lockingcollars abut a side of the central inner hub of the roller.
 24. Thefurnace of claim 22, wherein: the first inner surface includes aplurality of first depending tabs depending therefrom, the firstdepending tabs defining a first set of the slots; and the second innersurface includes a plurality of second depending tabs dependingtherefrom, the second depending tabs defining a second set of the slots.25. The furnace of claim 24, wherein: the first and second dependingtabs are integral with the central inner hub; and the first and seconddepending tabs are tapered in a direction moving away from the centralinner hub.
 26. The furnace of claim 25, wherein: each locking collarincludes a skirt surrounding the rotatable shaft, a flange extendingaway from the skirt, and the fingers; and the fingers extend away fromthe flange in a direction opposite to the hub.
 27. The furnace of claim26, wherein: the fingers taper in a direction moving away from theflange.
 28. The furnace of claim 27, wherein: each of the fingersinclude a tab extending therefrom, and each of the tabs abuts a side ofthe central inner hub of the roller.
 29. The furnace of claim 28,wherein: the tab extends in a direction parallel to the direction of theflange.
 30. The furnace of claim 16, wherein: the rotatable shaft ishollow.
 31. The furnace of claim 16, wherein: the roller assembliesextend obliquely to a line perpendicular to the direction of travel ofthe billet.
 32. The furnace of claim 31, wherein: the roller assemblieshave an upstream driven and a downstream roller end, such that therolling surface of the roller rotates and lifts the leading edge of thebillet.